Feminist; patriot; opportunist: Yuriko Koike, who was elected governor of Tokyo on July 31st, has been dubbed many things, not all of them flattering. A career of cycling through political parties without committing to any earned her the moniker Madam Kaiten Sushi, after restaurants where plates of raw fish go around on a conveyor belt, waiting to be plucked off. Her defining characteristic, however, may be her ambition.

Like Margaret Thatcher, whom she admires, Ms Koike is self-made and has battled through the nearly all-male ranks of her profession. (In this she differs from Makiko Tanaka, Japan’s first female foreign minister in the early 2000s, whose dad was a former prime minister.) Just 9.3% of lawmakers in Japan’s lower house are female, putting it 155th in the world. A member of the Liberal Democratic Party, she was defence minister in 2007 but missed her chance a year later to become Japan’s first woman prime minister when Taro Aso beat her to become party leader. She infuriated party bosses by running against their candidate, Hiroya Masuda, in the Tokyo election, trouncing him by more than 1m votes.

One reason Ms Koike captured the imagination of Tokyoites was her portrayal in the media as a plucky challenger of male-dominated politics. When one of her predecessors as governor, Shintaro Ishihara, said that running the capital should not be left to “a woman with too much make-up”, she laughed and said she was used to such insults. Japan’s sex barrier is not made of glass, she said, paraphrasing Hillary Clinton, but steel. She has made much of her aim to improve Japanese women’s lot. The country needs “the strengths of women: fortitude, steadfastness, tenacity”, she said in her manifesto.

However, Tomomi Yamaguchi of Montana State University says Ms Koike is more a nationalist than a feminist. As defence minister she fought for a tough line on China and she is one of the few Japanese politicians openly to call for Japan to have nuclear weapons. She helped run the parliamentary association of Nippon Kaigi, a conservative lobby that says Japan fought in the second world war to liberate Asia from Western colonialism, and which wants to restore lost family values. In all this she is rather like Mr Ishihara, a crusty hawk who loved to bait China—despite his ungallant words.

Ms Koike’s first task will be to rebuild confidence in her office: money scandals cost her two most recent predecessors their jobs. She will be running the world’s largest city-economy, with an estimated annual GDP of $1.5 trillion, built on one of the world’s most unstable seismic zones (the chance of a magnitude seven earthquake in the next three decades is estimated as 98%). And she must guide it to the 2020 Olympics, after two years of stumbling, costly preparations that have dampened public enthusiasm. Above all, she will have to find a way to navigate a political world that views her with a mixture of distrust and respect, but little affection.